Tuesday, March 15, 2011 | |
Radiation levels rise at Japanese nuclear plant
Top story: Japan faces the growing risk of a nuclear disaster at the Fukushima Daiichi Nuclear Power station. At this point, the level of radiation released has already made this the worst nuclear accident since the 1986 Chernobyl disaster.
There has been a significant spike of radioactivity around the plant, with levels at one point reaching 400 millisieverts an hour. That level of exposure means that workers at a U.S. plant would reach their maximum allowed annual dose in seven minutes, and exposure for 75 minutes would cause acute radiation sickness.
Engineers worked frantically to cool the most heavily damaged unit at the plant, reactor No. 2, by pumping in seawater. However, a malfunctioning valve at the reactor temporarily prevented workers from injecting new seawater into the unit. While this malfunction was eventually repaired, it caused the nuclear fuel to be exposed for a number of hours and damaged the reactor's containment vessel.
Most of the 800 workers at the Fukushima Daiichi plant have been withdrawn, leaving approximately 50 workers to combat the growing crisis. The breach of the No. 2 reactor could endanger the entire operation, because the leak of radiation may endanger the health of the remaining workers. If they are forced to evacuate, all three reactors at the plant will likely melt down.
Japanese Prime Minister Naoto Kan addressed the growing crisis this morning. "[A]lthough this incident is of great concern, I ask you to react very calmly," he said in a brief national address.
